Cleaning objects are required, or else the Excel object will not go away in Task Manager

While (System.Runtime.InteropServices.Marshal.ReleaseComObject(XBook_New) <> 0)
End While
XBook = Nothing
While (System.Runtime.InteropServices.Marshal.ReleaseComObject(XBooks) <> 0)
End While
XBooks = Nothing
XApp.Quit()
While (System.Runtime.InteropServices.Marshal.ReleaseComObject(XApp) <> 0)
End While
XApp = Nothing

For each object, do ReleaseComObject and then set its value to Nothing

If the spreadsheets are updated via a Loop, check carefully that every object is cleaned before it is called again.